Process for rolling screw-bolts.



a. HELLER. PROCESS FOR ROLLING SCREW BOLTS. APPLIDATIOK FILED JUHEQ, 1910.

1,017,543. Patented Feb. 13,1912.

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Patented Feb. 13, 1912.

2 SHEETS-SHEET 2 J. HELLER.

PROCESS FOR ROLLING SCREW BOLTS.

APPLICATION FILED JUNE 9, 1910.

UNITED STATES PATENT OFFICE.

JULIUS HELLER, OF VIENNA, AUSTRIA-HUNGARY, ASSIGNOR TO THE FIRM OF SCHRAUBEN- UNDSCHMIEDEWABENFABRIKS AKTIENGESELLSGHAI'T, BBEVIL- LIEB dc CO. UND A. URBAN & SbIiNE, OF VIENNA, AUSTRIA-HUNGARY.

PROCESS FOR ROLLING SCREW-BOLTS.

Specification of Letters Patent.

Patented Feb. 13, 1912.

To all whom it may concern:

Be it known that I, JULws HELLER, a subject of the Em eror of Austria-Hungary, residing at ienna, Empire of Austria-Hungary, have invented certain new and useful Improvements in Processes for Rolling Screw-Bolts; and I do-hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others it pppertains to make and use the same.

y invention relates to an improved process for rolling screw bolts.

The object of my invention is to provide an improved process of turning down the point or end of the bolt while the thread is elng rolled into the same. This process consists in moving the knife serving for turning down the end or point of the bolt during rolling in the thread relatively to the thread in the direction of the axis of the bolt. This is preferably brought about in the machine serving forcarrying into practice the said process by moving the nife in the direction of the axis of .the bolt by means of a guide on apart of the ma c 1 nc movin at right angles to the axis of the bolt whi e the thread is being rolled.

Simultaneously with the turning down of the end or oint of the bolt the bottom side of the bolt head may be turned down. For this purpose on the knife servin for turning down the end or oint of t e bolt an edge is provided whic acts on the bottom side of the bolt head. Further simultaneously with the turning down of the bolt end also the outer surface of the threads while being formed may be turned down in order to impartto the thread directly by the rolling a predetermined outer diameter. For this purpose the knife besides being moved in the direction of the axis of the bolt during rolling action is also moved at ri ht angles to the said axis.

11 the annexed drawings Fi ures 1 and 1" illustrate diagrammatically t e carr ing into practice of my improved process. ig. 2 shows in side elevation a machine adapted to carry into practice the said process. Fig.

3 illustrates a sectional view taken on line 3-3 of Fig. 2.

The thread is rolled into the bolt S in the well known manner by dies moving relatively and parallel to each other and at skilled in the art to which angles rightangles to the axis of the bolt so that the bolt rolls on both dies. Obviously one of the dies may be stationary and the other may move or both dies may move in opposite directions.

The knife M for turning down the end or point of the bolt while the thread 'is being rolled is moved according to my invention in the direction of the axis of the bolt. At the beginning of the rolling operation the knife M is in the position indicated by dotted lines in Fig. 1 in which position the edge 0 serving for turning down the end of the bolt is out of contact with the same. In the course of the rolling operation the knife M is moved toward the bolt in the direction of the axis of the latter whereby the edge 0 comes into engagement with the end of the bolt and turns it down to the desired extent as indicated in Fig. 1 in full lines.

At the ,end of the rolling operation the knife is moved back away from the bolt into the position indicated in dotted lines in Fig. 1 for releasing the bolt so that itmay be removed after rolling. Besides the movement in the direction of the axis of the bolt above described a movement at right angles to such axis may be imparted to the knife, as illustrated by Fig. 1 and the knife may be provided with a cutting edge 'M' parallel to the axis of the bolt. At the beginning of the rolling operation the knife M is out of contact with the bolt S as indicated in dotted lines in Fig. 1".

In the course of the rolling operation the knife M is moved toward the bolt not only in the direction of its axis for turning down the end or points of the bolt as above described, but also in a direction at right to-the axis of the bolt so that it reaches the position indicated by full lines in Fi 1". In this way the cutting edge M paral el to the axis of the bolt turns down the outer surface of the thread being formed.

The movement of the knife in a direction at right angles to the axis of the bolt is so governed that a predetermined outer diameter is imparted to the thread of the bolt directly by the rolling as disclosed in my prior Patent No. 967,768 of August 16, 1910. B rollin in the thread part of the metal of the bo t is forced outward so that the outer diameter of the thread obtained by so doin rolling would be greater than that of the shank of the bolt. If now the outer surface of the thread is turned down during rolling as set forth, the amount by which the outer diameter of the thread exceeds that of the shank may be reduced to any desired extent and even to zero or the outer diameter of the rolled in thread may be made smaller than that of the shank.

According to the desired outer diameter of the thread the cutting edge M of the knife M is more or less approached to the axis of the bolt in the course of the rolling operation but the knife must recede from the bolt before completing the rolling in order that the thread may receive exactly the contourof the dies. Simultaneously with the turning down of'the point or end of the bolt also the underside of the bolt head may be turned down by providing on the knife M a cutting edge acting on the said underside.

This cuttin edge is shaped to correspond with the desired contour of the underside of the bolt head. As shown in Fig. 1 this cutting edge Q is strai ht and at right angles to the axis of the heft so that it turns down plane the underside of the bolt head T. In it removes the bur U which is formed inpressing the head through a die hole. In Fig. 1 this second cutting edge K is so shaped that it turns down conically the underside of the bolt head. The edge Q or K must be in such a position relatively to the cutting edge 0 turning down the point of the bolt that the bolt head is finished at the same time as the bolt end. In order to insure this with certainty in all cases the cutting edge Q or K for the underside of the bolt head may be adjustable on the knife.

The movement of the knife in the direction of the axis of the bolt is imparted to the knife M by a. guide N, Figs. 1 and 1" on a part of the machine which during rolling moves relatively to the bolt and at right angles to its axis. This part is preferably the frame of the machine if one of the dies is fast in such frame and the other is inovable. If the dies move in the frame in opposite directions and with the same speed so that the bolt does not move at right angles to its axis relatively to the frame durln rolling, the guide N will have to be arranged on one of the dies.

The construction of a machine adapted for carrying into practice the above described rocess does not form part of this application. In Fig. 2 I have shown such a machine for clearly illustrating my process, and in this figure only one of the dies as indicated at B is moved while the other die B is stationary and. the bolt moves during rolling with half of the speed of the movable die at right angles to its axis. In this case the knife M must move in the frame at right angles to the axis of the bolt. This is done by guiding the knife M in a slide F in the direction of the axis of the bolt while the slide F is guided in the frame of the machine at right angles to the axis of the bolt. The slide l* is reciprocated in this direction by a link E operated by a cam D mounted on a revolving shaft. The movable die is reciprocated by a link Cl pivotally connected with a crank pin on the said cam. For better guiding the link E its end engaging with the cam D may be pivotally connected with a crank arm E mounted on a shaft E journaled in the machine frame. For deadening shocks the link E may be made in two parts between which a spring E is interposed as shown in Fig. 2.

The movement of the knife M in the direction of the axis of the bolt is brought about by a guide N secured to the frame of the machine on which the knife runs preferably by means of a bowl. The guide 18 provided with inclines which move the knife toward and away from the bolt with the required speed. The cam groove in the cam is so shaped that at the beginning and at the end of the rolling operation the knife so far recedes from the bolt in a direct-ion at right angles to its axis that the bolt niay be conveniently put in and removed from the machin. V

The movement of the knife relatively to the axis of the bolt and at right angles to the same in the course of the rolling operation (if according to the rocess illustrated by Fig. 1 the outer sur ace of the thread has to be turned down) is secured by pro erly shaping the cam groove in the cam Instead of one knife M two or more such knives may be used which are carried by different slides F actuated by difierent cams. Each of suchknives may be provided with one or more of the cutting edges servin for turning down the point or end of the olt, the underside of the bolthead and the outer surface of the thread.

Claims.

1. A process for rolling screw bolts consisting in causing dies to move relatively and parallel to each other at right angles to the axis of the bolt and in contact with the bolt whereby the bolt is caused to roll along both dies and in causing a knife to move in the course of the rolling operation relatively to the bolt in the direction of its axis whereby an edge of such knife turns down the end of the bolt.

2. A process for rolling screw bolts consisting in causing dies to move relatively and parallel to each other at right angles to the axis of the bolt and in contact with the bolt whereby the bolt is caused to roll along both dies and in causing a knifefto move in the course of the rolling operation relatively to the bolt in the direction of its axis whereby an ed e of such knife turns down the end of relatively to the bolt in the direction of its the be t and another edge of such knife turns axis and also in a direction at right angles down the underside of the head of the bolt. to its axis, substantially as and for the pm- 3. A process for rolling screw bolts c0n pose described.

5 sisting in causing dies to move relatively In testimony whereof, I afiix my signa- 15 and parallel to each other at right angles ture, ixrpresence of two witnesses. to the axis of the bolt and in contact with JULIUS HELLER- the bolt whereby the bolt is caused to roll Witnesses: along both dies and in causing a knife to ARTHUR BAUMANN,

10 move in the course of the rolling operation, AUGUST FRUGGER. 

